Refrigerating apparatus



Marh 13, 1934. M, Q TERRY 1,950,638

EEFRIGERATING APPARATUS Filed NOV. 1929 INVENTOR Wafsm 6. 75/7" ATTORNEY Patented Mar. 13, 1934 narmcnnarme arrana'rns Matson (3. Terry, Mansfield, @hic, msignor to Westinghouse Electric dz Manufacturing 80m parry, a corporation of Eennsyivania Application November 11,

nary degree of efficiency, reliability and effectiveness.

.It has for a further object to provide a compression refrigerating apparatus comprising essentially a compressor for translating and compressing refrigerant vapor-,-a motor for driving the compressor, a condenser for liquefying the compressed refrigerant vapor and an evaporator for absorbing heat from the elements to be cooled and, incidentally, for vaporizing the liquefied refrigerant, and an improved means for cooling the condenser which shall be especially applicable to refrigerating machines wherein the motor and the compressor are both totally enclosed in a fluid-tight or hermetically-sealed casing.

My invention has, for another object, to provide a fan, together with an improved means for driving the same, which fan shall be located exteriorly of the casing enclosing the compressor and the motor but shall be motivated by the latter without, in any way, affecting the fluid-tight qualities for hermetically sealing the casing enconstructed, a separate compressor and a motor for driving the same have been provided with an external drive shaft for connecting the motor to the compressor. Such refrigerating machines, however, require the provision of a stuffing icon or gland for the shaft connecting the motor to the compressor in order to prevent the escape of refrigerant fluid from, or the infiltration of air into, the compressor housing. The provision of such gland is, however, undesirable for the rea-=.

son that it must be adjusted or attended to irequently if it is to maintain a seal about the drive shaft which shall be entirely fluid tight and, unless it is so maintained, there is apt to he either a leakage of refrigerant fluid out of the system or an infiltration of air into'the system. As a refrigerating machine of the household type has Serial No. ltl iflilil se inar 0 map i o me s'rarss PATENT orrlca a relatively small volumetric capacity, a slight amount of leakage of refrigerant or infiltration of air will interfere materially with its successful operation. Refrigerating machines of this character are generally referred to as of the open type.

It has, therefore, been proposed to have the compressor and its driving motor located in a single hermetically sealed casing which may be to as of the enclosed type.

With refrigerating machines of the open type,

a fan is usually provided for circulating cooling air over the condenser which may be readily connected or coupled to the external drive shaft connecting the motor to the compressor. Then again, it may be embodied integrally with the fly wheel provided on the compressor.

However, with refrigerating machines of the enclosed type, the fan for circulating cooling air over the condenser must necessarily be located exteriorly of the casing which encloses the motor and the compressor and, to drive this fan by connecting or coupling the same mechanically to either the motor or the compressor inside of the casing, would involve the provision of a fan drive shaft extending through the casing and, hence, the entire basic idea of providing a totally enclosed hermetically sealed system would be de feated. It has, therefore, been proposed tc provide a second or separate motor for driving the fan, which motor is located exteriorly of the enclosing casing and directly coupled to the fan. Preferably, the arrangement is such that the separate motor-driven fan draws cooling air over the condenser and discharges it over the casing enclosing the motor and compressor, so that the condenser, the motor md the compressor are effectively cooled. However, the latter arrangcinvolves the provision of ment is objectionable in some respects in that it two motors, together with starting and control apparatus for each.

Furthermore, a -motor cl very small capacity is driving the compressor.

In addition, the proapparatus because of the necessity of providing an enlarged condenser surface, as compared with a condenser cooled by a forced draft, even taking into consideration the cost of the fan and its driving means, and, in addition, interferes with the compactness of the refrigerating-machinery. In other words, in order to obtain the same condenser efiiciency, using the natural radiating surface of the condenser only, it' is necessary to use an inordinately large amount of expensive condenser material, as compared with the amount of condensing surface necessary when forced air circulation is used.

I have, therefore, conceived the idea of providing, in enclosed refrigerating machines, a fan for effecting a forced circulation of air over the condenser, and, preferably, in addition, over the casing enclosing the motor and the compressor, or, in the event that the casing is adapted to act as the condenser, over the casing alone, and of having such fan driven inductively from the mo tor located inside the enclosing casing. By means of such arrangement, only one motor is required, and the hermetically sealing of the enclosing casing is not, in any way, affected or interfered with.

In my copending application, Serial No. 316,068, filed October 30, 1928, now Patent No. 1,819,528,

patented August 18, 1931, I have described one form of my invention which contemplates the use of permanent magnets mounted on one end of the motor shaft within the sealed casing. These magnets drive, by magnetic or inductive action, a conducting member mounted on a shaft outside the sealed casing, which shaft carries the fan for cooling the condenser. A rigid, nonmagnetic partition is interposed between the driving and the driven parts of the magnetic coupling and constitutes one wall of the enclosing casing.

The form of the invention described herein contemplates the use of a motor provided with two rotors. The motor field winding and one of the rotors is located entirely within the sealed casing. This rotor drives the compressor. The second rotor is located outside the casing and drives the fan. A non-magnetic high-resistance partition is interposed between the second rotor and the field winding, this partition constituting one wall of the sealed casing enclosing the field and the first rotor.

Referring to the drawing for a detailed description of my invention, I provide a sealed casing 10 comprising a cylindrical member 11 and removable end cover plates 12 and 13.- The end plate 13 comprises a cup-shaped member14 provided with a flanged portion 15. The flanged portion is secured to a ring- 16, preferably by welding or brazing. I have found that, to secure the most efficient operation of my invention, the member 14 should be formed of non-magnetic, highresistance material. A ring 1'7 is provided with openings 18 for receiving bolts 19 which also extend through openings provided in the ring 16. Thering 17 holds the end cover plate 12 in position against the cylindrical portion 11, and, when the bolts 19 are tightly drawn, the ring 16 and the cover plate 12 are forced against the opposite ends of cylinder 11, thereby providing a sealed casing.

Within the casing 10 are located the refrigerant .compressor 20 and the driving motor 21. The shaft 22, connecting the motor to the compressor, is mounted in a bearing 23 formed integrally with the web 24. The rotor 25 of the motor is connected to one end of the shaft, and the other end of the shaft carries a crank 26 on which is mounted the connecting rod of the piston 27. The piston reciprocates in a cylinder 28. Details of the motor and compressor structure, together with the lubricating means therefor, are described in the copending application of Frank Conrad and Christian Aalborg, Serial No. 204,401 filed July 8, 1927 and assigned to the Westinghouse Electric 8; Manufacturing Company. It is, of course, understood that the invention in the present case may be used with any type of compressor.

According to my-invention, the stator or field 29 of the motor extends beyond and surrounds the sides of the cup shaped wall member 16. A second rotor 30, located outside the sealed cesing 10, extends into the depression provided in member 13. By this arrangement, the rotor is actuated inductively from the winding 26st the same time that rotor 25 is actuated to operate the compressor 20. The non-magnetic cupshaped member 13 is interposed, however, between the stator 29 and the rotor 30. To achieve the most efficient operation of the rotor 30, it is necessary that the gap between the wall and the stator 29 on the one hand, and the gap between the wall and the rotor 30 on the other hand, shall be maintained as small as possible.

The rotor 30 is mounted on one end of a shaft 32 which is supported in a bearing 33 formed in a web 34. The web 34 is provided with a flange 34 through which the bolts 18 likewise extend, thereby supporting the whole structure in a compact assembly. The shaft 82 carries a fan 37 on its end opposite the rotor.

The shaft may be supplied with lubricant from an oil cup 38, the lubricant passing from the cup through an opening 39, thence along the shaft inwardly to a groove 40, from which oil is returned to the cup by a passageway 41 formed in the web 34.

In the operation of the refrigerating apparatus embodying my invention, expanded refrigerant medium is drawn from the evaporator 42, through a conduit 43, to the compressor 20. The compressed gas is discharged from the compressor to the interior of casing 10, from whence it is forced into a conduit 44 leading to the condenser 45. Energization of the motor field causes the operation-of both rotor 25 and rotor 30. Rotor 25 drives the compressor, and rotor 30 drives the fan 37, thereby causing a blast of air to be forced over the condensing coils 45 and the casing 10.

Condensed refrigerant passes from the condenser to the receiver 46 and thence, through the pressure-reducing valve 4'1, to the evaporator when it expands, absorbing heat from the chamber to be cooled. Ice-forming trays, as indicated at 48, may be within the evaporator.

While I have shown and described a single form of my invention, it will be apparent that ioo other forms may be adopted, all coming within the scope or the appended claims.

I claim as my invention:

1. Refrigerating apparatus comprising a compressor, a condenser and an evaporator, operative interconnections between said parts, means for circulating air over the condenser, a motor, said motor comprising a single stator and two rotors, one of said rotors driving the compressor the other rotor driving the air circulating means, and a sealed partition between said rotors.

2. Refrigerating apparatus comprising a compressor, a condenser, and an evaporator, operative interconnections between said parts, a fan for cooling the condenser, a motor comprising a stator and a plurality of rotors, and a sealed casing enclosing said compressor, said field mag net and one of the rotors, a second rotor being (iii located outside the casing and operatively con nected to the fan for driving the same,

8. In refrigerating apparatus, the combination of a compressor, motor means. a sealed casing enclosing the compressor and a portion of the motor means, an evaporator, a condenser and means for circulating air over the condenser, said circulating means being disposed outside the sealed casing and said motor means comprising two rotors and a common stator, one of said rotors being disposed .within the casing for driv ing the compressor and the other rotor being disposed outside of the casing for driving the MATSON C. TERRY. 

